This invention relates to the fabrication of conductive polymer material, also known as conductive polymer interconnect (CPI) material.
There is, at present, a great deal of interest in polymer material which is anisotropically electrically conductive. Such material can be employed, for example, in surface mounting of semiconductor components, in socket fixtures and in testing apparatus. One type of such material includes chains of conductive particles which are magnetically aligned in columns in an elastomeric matrix to provide the conduction in only the thickness (z) dimension of the resulting layer (See, for example, U.S. Patent Application of Jin et al, Ser. No. 936,998 filed on Dec. 4, 1986, now abandoned, assigned to the present assignee and incorporated by reference herein). Electrical connection is achieved upon compression of the elastomeric material between opposing contact areas. Due to the processing methods, the through resistance of the materials is not always at a desirably low level, e.g., less than 250 m.OMEGA., especially when the loads applied to the layer are small (e.g., less than 25 lbs.).
It is, therefore, an object of the invention to provide conductive polymer interconnect material with consistently low through resistance.